Image Plane with Alpha Transparency, I want to remove lighting effects
Mix your Image texture (through a shader - emission is possible) with a Transparent Shader, using your images' alpha as a mix factor. As you can see in the image bleow, there are no lights in the scene. It works in both cycles and EEVEE, but keep in mind, in Cycles it will actually emit light without further modification to the shader. If using EEVEE, remember to switch the material's blend mode to something other than opaque: